A Novel Hierarchical Structured mCeO2 NR/Mn3O4/Pt as an Efficient Catalyst for Low-Temperature Toluene Combustion

The binary metal oxide-based catalysts have been proven to exhibit superior catalytic performances than their single metal oxides. As active supports, the physical and chemical properties of metal oxides would influence the chemical and electronic interactions with noble metal nanoparticles. By precise control of the composition and structure of metal oxides, the synergistic interaction between noble metals and transition metal oxides is expected to be realized. Herein, a novel hierarchical structured mCeO(2) NR/Mn3O4/Pt catalysts were designed for low-temperature toluene combustion. The mCeO(2) NR/Mn3O4 composites were fabricated by a simple and effective two-step sequential hydrothermal synthesis approach. After subsequent loading of Pt nanoparticles over mCeO(2) NR/Mn3O4 by impregnation and reduction methods, the mCeO(2) NR/Mn3O4/Pt catalysts with hierarchical structure were successively synthesized. The catalytical performances of the catalyst were evaluated by the toluene oxidation reaction. It was observed that the catalytic activities of the catalysts were closely related with the contents of Pt and Mn3O4, and mCeO(2) NR/Mn3O4/Pt with 2.1% Mn and 0.45% Pt exhibited the greatest catalytic activity (T-95 = 165 ?) toward the oxidation of toluene. The apparent activation energy for toluene oxidation with mCeO(2) NR/Mn3O4/Pt (2.1% Mn) was as low as 35.3 kJ/mol. The improvement of the catalytical performance was due to the synergistic effect between CeO2 and Mn3O4 that led to the increase of oxygen vacancies and the enhancement of redox capacity, and the good dispersion of Pt active sites over the mCeO(2) NR/Mn3O4.